Testing tap water?

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

AdamHorton

Aquarium Advice FINatic
Joined
Aug 12, 2009
Messages
581
Location
Cincinnati, OH
I'm toying around with the idea of getting an RO/DI unit for my tap water, but I already have a filtration system on my kitchen sink so I'm not sure how much my tank will benefit from it. I have a 150G SW tank with live rock that one day hopes to be a reef. I don't know what kinds of corals I want to get yet, probably lots of different ones, but I want as many options open as possible so that when the time comes to plan for corals and anemones, I have lots of freedom.

My question is this: how exactly do I test my tap water to see what kind of benefit RO/DI will do for me? What types of measurements should I be looking for? What will they mean? I'm sure there are articles you can point me to but if anyone has personal experience that would help out a lot too. Thanks,
 
Nitrates, phosphates, nitrites, ammonia, and copper are about the only thing that you can easily test for - and probably worth measuring. Picking up a TDS meter (TDS = total dissolved solids) and measuring the TDS of the water will help you too - bigger numbers means there's lots of other crud in there that could really be anything.

But in the end - and this is from personal experience - even if your water tests "perfect", it doesn't mean it is. Our test kits just don't pick up trace levels of stuff that's in the water that will end up building up over time in our tank. In addition, just because the water tests fine one day doesn't mean it will be fine the next. For example, the incoming water to my house for 2 years has been around 80ppm TDS, regardless of the season. Within the last 3 weeks, it's dropped to around 30ppm TDS. That's a good thing... but it could've just as easily swung the other way. And why it did that... who knows.

The point is... if you want consistant water parameters in your source water, RO/DI is the only way to guarantee that. Do you need RO/DI to run a reef tank? No - plenty of people don't use it. But without it, you're at the mercy of a lot of factors (water department, seasonal water runoff, local fertilizer use by farmers, piping in your house, etc) that you have absolutely no control over.

Also... home filtration systems most likely strip the chlorine out of the water, and knock the big stuff out, but will most likely let a lot of stuff by. In testing my "Brita" water - with water from the tap at 80ppm TDS, the water run through a Brita filter comes out about 45ppm TDS. So yeah... it's taking some stuff out of the water, but leaving behind a lot.
 
silicate (spell right?) is another thing home filtration probably won't able to pick up, which is one of the cause of diatom bloommmmm.
 
Kurt nailed what you want to look for. I think TDS is really the key in seeing what you got.

What kind of filter do you already have? If it's just a charcoal filter, then it's really not doing a whole lot for your tank IMO.

How long have you been running your tank without the RODI?
 
The filter I run now is a wet-dry trickle filter, connected to a small refugium (10G tank). Here's a picture of the most recent setup:

http://www.adamhorton.com/files/refugium3.jpg

So I need to test for TDS. I did a quick search and most things that measure TDS are electronic. Can I buy one of those without ordering one online? Any recommendations on what kind is best?

...and match, if you didn't ask it I would have :)
 
The filter I run now is a wet-dry trickle filter, connected to a small refugium (10G tank). Here's a picture of the most recent setup:...

Think he meant what kind of water filter is in the house that you've been using...

So I need to test for TDS. I did a quick search and most things that measure TDS are electronic. Can I buy one of those without ordering one online? Any recommendations on what kind is best?

Yup... they're electronic. I have a cheapo Hanna Instruments and it works just fine. And yeah... you can buy ANYTHING without ordering online! :lol: It just depends on how far you want to drive to get it! Any store that deals with water quality issues or testing should sell them.
 
"And yeah... you can buy ANYTHING without ordering online!"

Wow, you must be OLD ....

I got mine for about $20 shipped off ebay. Honestly I've never seen them in a brick-n-mortar lfs. Wouldn't know where to shop for one..
 
I see about the filter: it's a Filtrete system that goes on the pipes leading up to the kitchen sink. If you need more details on it I can get them.

Do you think I could find a TDS tester at my hardware store?
 
"And yeah... you can buy ANYTHING without ordering online!"

Wow, you must be OLD ....

If I remember right, I think you've got a couple years on me! At least I can still remember back in the day when stores actually sold stuff and just didn't display it so you could order it online! :lol:

But honestly... I got mine online too. Stuff like that will easily cost you 2x the online price if you buy it in a store. But places that sell water filter systems should be able to sell you one. Not sure if swimming pool supply places would stock them. Shoot... I even saw one at my local homebrew supply store the other day! That surprised me!
 
Back
Top Bottom